Children's ride-on vehicles are reduced-scale vehicles that are designed and sized for use by children. For example, children's ride-on vehicles include a seat adapted to accommodate one or more children as well as steering and drive assemblies that are adapted to be operated by a child sitting on the seat. The drive assembly is adapted to drive the rotation of one or more of the vehicle's wheels and may include a battery-powered motor assembly or a manually powered drive assembly, such as a pedal-powered drive assembly.
The wheels used on children's ride-on vehicles are often blow-molded from a suitable material, such as a plastic. Blow-molded wheels are conventionally formed using a mold that has two portions. The portions of the mold collectively define a cavity that defines, or corresponds to, the shape of the blow-molded wheels. During the blow-molding process, a parison of molten plastic is introduced into the mold cavity and a pressurized gas, such as air, is used to force the molten plastic against the internal surface of the cavity in order to form a hollow wheel having a shape defined by the internal surface of the cavity. After a brief cooling period, the mold portions are separated, typically in an axial direction.
Each of the mold portions may include what is referred to as a pinch-off ring that may squeeze and/or cut the parison of molten plastic that is inserted into the mold to produce the wheel (when air is injected to inflate the parison against the interior surface of the mold). In particular, as the mold portions close on and/or around the parison, the pinch-off rings come together to cut and/or pinch off the portion of the parison that remains outside the mold cavity. The pinching effect of the pinch-off rings may leave a seam, or part line, on the finished wheel.
The part line caused by the pinch-off rings often lies in a plane passing through the center of the outer circumference of the wheel. Conventionally, this plane is often normal to the axis of the wheel. In such a configuration, the part line may define the central circumference of the wheel. Typically, the pinch-off rings have a circular geometry such that the circumferential seam, or part line, on a blow-molded wheel has a uniform diameter around the circumference of the wheel. In particular, the central circumference of a blow-molded wheel is typically circular in shape. The central circumferential region of the wheel includes a circular ground-contacting, or “run-flat,” surface of the wheel, which conventionally is approximately one inch wide. On such a wheel, the part line is typically centered in the run-flat region. Examples of blow-molded wheels having circular central circumferential regions are shown in U.S. Pat. Nos. 4,513,981 and 5,368,371, the complete disclosures of which are hereby incorporated by reference for all purposes.
Children's ride-on vehicles are subject to being driven on a variety of surfaces, including concrete, dirt, and grass, as well as up and down hills. Oftentimes, ride-on vehicles must surmount various obstacles on the driving surface, such as sticks, rocks, curbs, tool handles, hoses, pieces of lumber, etc. However, the ability of wheels that have a circular central circumferential region to surmount such obstacles, or otherwise engage a given driving surface, is generally limited to the frictional engagement between the circular ground-contacting surface of the wheel and the obstacle or driving surface. The wide range of potential obstacles and driving surfaces that may potentially be encountered by a ride-on vehicle make it desirable to provide a wheel that may more readily engage and travel over a greater degree of obstacles than conventional blow-molded ride-on wheels.